| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a safety system for preventing a collision of a support with another parts, for a lithographic apparatus which has a stationary magnet motor for driving the support such as a substrate support or a patterning device support. <P>SOLUTION: A measurement system for measuring the position of the support. The measurement system measures a magnetic field strength of an alternating magnetic field generated by a magnet assembly of the stationary magnet motor, and/or measures generation of eddy currents in a metallic layer shielding the magnet assembly in combination with an inductance measurement of an electromagnet generating the alternating magnetic field causing the eddy currents, and/or measures light using an optical position sensitive sensor such as a CCD metric or linear photodiode positioned in a light plane emitted by an emitter. <P>COPYRIGHT: (C)2009,JPO&INPIT |
